Wood weight calculator
Weight of timber from its volume, species and moisture content.
Fill in the fields and the result will appear here automatically.
Converts timber volume to mass using six fixed density parameters and a chosen linear moisture adjustment. Within this model, oak at 12% is 700 kg/m³ and spruce 450 kg/m³, a difference of about 55.6%, not one third. The density used is shown separately. Actual species, moisture, volume change and batch variation can give a different mass; this model does not approve a vehicle load.
How it works
Formula and logic
Fixed parameters at 12%: pine 520, spruce 450, birch 650, oak 700, larch 660 and aspen 490 kg/m³. The chosen model is ρ = ρ12·(1 + (M − 12)/100), mass = V·ρ. M is water mass relative to oven-dry wood mass, as a percentage. This product supports 0–100%; that is not a physical maximum moisture content. V is positive and finite. The six parameters and linear correction are not verified as universal species densities; volume change, precise botanical species and batch variation are not modeled.
Example
One cubic metre of pine at 12 % moisture weighs 520 kg.
Fields and units
- Volume — m³
- Species — list option
- Moisture content — %
How to use
- — Enter actual volume in m³.
- — Choose a fixed species parameter and check the displayed density.
- — Enter moisture relative to oven-dry wood mass; this product range is 0–100%.
- — Use measurements for actual batch mass rather than the selected parameter alone.
Method and limitations
- Calculation method
- Formula and logic
- Data or methodology source
- USDA Wood Handbook, chapter 4: dry-mass moisture and density variation; not verification of model parameters
- Limitation
- Mass is an estimate from fixed parameters and a linear correction. Actual batch measurements are needed for loads; the wood-properties source does not verify the six model parameters.
FAQ
Why does moisture change the weight so much?
Because water is part of what you are lifting. Freshly felled softwood can be half water by weight, which is why a green log and a seasoned one of the same size feel like different objects.
Where does 12 % come from?
12% is the selected reference state of these parameters, not a guaranteed indoor timber moisture level. Equilibrium moisture depends on air temperature and relative humidity. Enter measured moisture and do not confuse it with water as a fraction of total wet mass.
Is the linear adjustment accurate?
It is a retained product simplification, not a verified law for every species. Moisture changes both timber mass and volume; this model changes density only along its chosen line. A consequential batch estimate needs measurements; a computed number does not establish loading suitability.
Does this work for boards as well as logs?
Yes, if you enter the actual volume. The board volume calculator will give you that figure from dimensions and count.
Why is my species not listed?
The list is limited to six fixed product parameters. A species name does not identify the precise botanical species or batch density. Do not treat the nearest listed name as a verified density for another material.